Carts that connect to each other to form a train of carts towed by a tugger are used to transport materials in a warehouse. Commonly, each cart has a chassis supported on wheels, a hitch at the rear end of the chassis, and a drawbar at the front end of the chassis. The distal end of the drawbar of each chassis is configured to be coupled to the hitch of an adjacent cart. An existing configuration for the drawbar and hitch coupling involves a hitch that includes a rearward extending plate with a vertically oriented aperture (“hitch hole”). The drawbar terminates in a downwardly extending boss (“the boss”) configured to be received in the aperture of the hitch hole. Typically, the drawbar is configured to pivot at least about a horizontal axis. The boss of one cart conveniently connects to the hitch hole of another cart by simply pivoting counter clockwise (upward) the drawbar and aligning the boss with the hitch hole. Once aligned the boss of the drawbar can be lowered into the hitch hole. The connection between the boss and the hitch hole allows the boss to pivot relative to the hitch hole about a vertical axis, thereby allowing the carts to track in a line when pulled.
The existing configuration is simple, which is desirable. There are very few moving parts to maintain and the coupling of a drawbar to a hitch is fast and efficient. However, a disadvantage of the current system is that the carts can inadvertently disconnect if the drawbar pivots counterclockwise, which can happen if the carts travel over a bump or if they are stopped abruptly. The present disclosure provides a system and method that preserves the advantages of the existing system while also addressing its drawbacks.